Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KUNR 221712
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1112 AM MDT MON AUG 22 2016

.UPDATE...
Issued at 1029 AM MDT Mon Aug 22 2016

Upper level ridge is amplifying across the Northern Plains as SW
Canadian Low drops south along the Northern Rockies. Other than a
few high clouds and haze from smoke, should see mostly sunny skies
today with very warm temperatures. Most locations across the
plains should see high temperatures in the low to mid 90s. As a
weak surface trof shifts into the Black Hills region, west to
southwest winds will become breezy across parts of Northeast WY
and southern SD. The combination of breezy winds and very dry air
will produce high fire danger across this area through the early
evening hours.

&&

.SHORT TERM...(Today Through Tuesday Night)
Issued at 125 AM MDT Mon Aug 22 2016

Broad upper ridge covers the central CONUS, with the next trough
pushing into the Pacific Northwest. Skies are clear over the
northern plains. Surface trough is moving into the region, and
winds are generally southerly ahead of it. Some breezy
southwesterly downsloping winds over the northern foothills are
keeping temperatures in the 70s there, while the rest of the
area is in the 50s and 60s.

Upper and thermal ridge axes will cross the area today, resulting
in very warm temperatures in the 90s and around 100 over central
SD. As surface low slowly passes through, westerly winds will
increase across northeastern WY and southwestern SD, with breezier
southwest winds over south central SD. Gusty winds over south
central SD are expected to continue overnight, keeping that area
in the upper 60s for lows. Areas farther north and west will be in
the 50s.

Upper trough will begin moving through the northern plains on
Tuesday, bringing a cold front through the region. Northwest winds
will become breezy across the western SD plains. Conditions will be
generally dry and stable on Tuesday, although some instability and
moisture over far south central SD may allow for a few showers and
thunderstorms to develop there and eastward in the afternoon and
evening. Highs will range from the 70s across northeastern WY and
the Black Hills to the lower 90s across south central SD.

.LONG TERM...(Wednesday Through Sunday)
Issued at 125 AM MDT Mon Aug 22 2016

Progressive but amplified flow expected in the period. A strong
cold front will bring fall like temps to the area once again wed-
thur. Otherwise, a slow warming trend is anticipated into the
weekend. Unsettled westerly flow will bring chances for showers to
the region wed night into Friday. Limited moisture per westerly
flow with poor to nonexistent gomex return flow will only support
a couple tenths of an inch of precip at most with each round of
shra. Hence, overall dry conds will persist.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Tuesday)
Issued At 1109 AM MDT Mon Aug 22 2016

VFR conditions are expected through the period. Gusty southerly
winds are expected through this evening, especially over far
southern south dakota. a sharp cold front tuesday morning will
bring gusty northwest winds.

&&

.FIRE WEATHER...
Issued At 125 AM MDT Mon Aug 22 2016

An upper level and thermal ridge will peak Monday, bringing a
deeply mixed boundary layer and very dry minimum relative humidity
values. Readings from 8-15% are expected across the southwest
third of the area Monday afternoon and evening with 15-25% across
the rest of the region. Expect gusty winds to mix down across the
very dry areas of northeastern WY and southwestern SD today, so
will upgrade to a Red Flag Warning. Additionally, stronger
southwest winds with gusts near 35 mph are forecast for south
central SD. With min RH values near 15% on the western side of
this zone, will include south central SD in Red Flag Warning as
well.

A cold front will slide through the area Tuesday with gusty
northwest winds on the SD plains most of the day. Still appears
that minimum RH values near 20% will preclude headlines at this
point.

&&

.UNR Watches/Warnings/Advisories...
SD...Red Flag Warning until 7 PM MDT this evening for SDZ263-265.

WY...Red Flag Warning until 7 PM MDT this evening for WYZ259-298.

&&

$$

Update...15
SHORT TERM...Pojorlie
LONG TERM...JC
AVIATION...Helgeson
FIRE WEATHER...Pojorlie


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.